Emerging Infectious Diseases and Disease Emergence: critical, ontological and epistemological approaches

This paper provides an introduction to the history of the concept of “emerging infectious diseases” (EID) and reflects on how humanities and social science scholars have interacted with it. It starts with a chronological outline of the coinage of the concept in the early 1990s in the wake of the shocks provoked by Ebola and HIV/AIDS, which disrupted the idea that the West was transitioning from a period of infectious diseases to one of chronic diseases. We argue that humanities and social science scholars in disciplines such as history, anthropology, STS, and literature studies have critically explored the concept, showing how entrenched it was in the perceptions of the US and Europe about threats posed by the rest of the globe. Moreover, we explore how scholars in the humanities have used the EID concept to comment on contemporary realities and mobilized it to create dialogues with scientists, especially during the COVID-19 pandemic. Subsequently, we explore how the growing contemporary interest in EID has pushed historians to research the ontological and epistemological factors that enabled the “emergence” of diseases long before the invention of the EID concept, such as plague, Chagas disease, and sleeping sickness, as well as the factors that transformed these and other emerging diseases into pandemics. We conclude by outlining a few neglected factors in the EID literature that could be addressed: the circulation and reception of the concept outside of the West, the examination of EID as a problem for wild animals and not just for humans, and global histories of disease emergence as an epistemological and social process.

. 14 It has since been deployed to encompass a myriad of diseases: from once "defeated" resurging diseases such as tuberculosis in the USA, 15 to new diseases like SARS or COVID-19, to pathogens, like anthrax, that might be used by bioterrorists. 16EIDs also brought renewed attention to the need for rapid international responses to emergence events.Thus, the WHO developed strategies in the 1990s to respond to outbreaks in as little as twenty-four hours. 17In 1997, the WHO established the GOARN (Global Outbreak Alert and Response Network), a network of 120 partners which enabled the rapid global dissemination of information. 18spite such lofty, global goals, EIDs were mainly framed as threats to the West: problems "out there" that thanks to globalization could become local problems.According to Nicholas King, emerging infectious disease research gained both traction and funding by "reframing 'international' problems in language palatable to American interests," such as border security and terrorism. 19The threatening nature of such diseases ushered in a new era of what Andrew Lakoff calls "global health security." 20No longer was it a question whether new diseases would be detected, but how best to predict and contain them. 21This framing of EIDs as global threats to the US sparked initial criticism of the concept as Americentric. 22owever, the concept was also adapted and recreated as it circulated around the world. 23or instance, various African scientists have described diseases like Ebola and Lassa fever as EIDS, though they are not a problem in distant and exotic places, but are threats to the local African population. 24The recent monkeypox pandemic is perhaps an ideal example of both points: a largely neglected disease known in West Africa since 1970, became an 'emerging' global concern after its appearance in the UK in 2022. 25Simultaneously, its spread has provoked alarm in other parts of the African continent, such as South Africa, where it was described as "another emergent virus." 26side from its successes as a concept in the field of public health, broader intellectual questions posed by disease emergence have interested humanities scholars long before the 1990s.In what follows, we highlight firstly how scholars have taken the EID concept as the object of their enquiry or employed it as a critical tool.Secondly, we examine how historians have tracked the emergence of diseases through synthesizing scientific knowledge and history.Finally, we discuss some of the approaches taken within the historiography of "framed" diseases: the epistemological appearances of new diseases, or the transformation of old scourges, by emphasizing changes in science and society.

Emerging infectious diseases: a disputed concept
The first means by which scholars have engaged with the concept of EIDs is in defining it as their object of enquiry.In this section, we analyze the critical examinations given by historians, anthropologists, and literary critics.One early example of the historical engagement with the EID concept is found in the work of medical historian Mirko Grmek.In a 1993 essay, Grmek proposed five conditions according to which a disease could be considered as emerging in the present or in the past. 27Grmek's categories stressed biological processes but also highlighted how social and scientific changes could make visible phenomena that had until then been ignored.This is a point that is sometimes missed by scientists. 28re recently, historians have used the concept of EIDs as a critical tool to intervene in current debates both in public health, and history itself.Brian Dolan's work reveals that underlying governmental models of pandemic preparedness were based on the assumption that the "next pandemic" would be a mutation of influenza.This assumption left governments unprepared, in early 2020, to deal with a coronavirus pandemic. 29Jon Arrizabalaga has interpreted the profusion of emerging diseases in the last few decades as proof of the risks brought by modernity.He argues that many well-known emerging diseases were created by the pharmaceutical industry -bacteria resistant to antibiotics, among others -or by the development of agriculture.To him, the pessimistic view that modernity itself is a source of disease emergence has been proven by the ongoing COVID-19 pandemic. 30ile these historians have drawn upon the past to critique the present, a few others have demonstrated how the concept of EIDs is indebted to the past.Early-to mid-twentieth century disease ecological thinking developed in colonial settings was often overlooked in twentieth century Western public health campaigns, but took centre stage after the Outbreak a Cause for Concern as SA Records 5th Case," Eyewitness News, 19 August 2022, https://ewn.co.za/2022/08/19/phaahlasays-monkeypox-outbreak-a-cause-for-concern-as-sa-records-5th-case. 27 da Silva and Skotnes-Brown emergence of HIV/AIDS and Ebola. 31Indeed, both Joshua Lederberg and the virologist Robert Shope stressed that epidemics did not "strike societies randomly or in accord with the caprices of angry gods," but instead reflected "relationships that human beings establish with one another and with the natural and built environments," spreading across "fault lines created by demography, poverty, environmental degradation, warfare, mass transportation, and societal neglect." 32For Warwick Anderson, such analyses signal a recognition that the developed world had "finally read the ecological lesson" provided by disease ecologists in colonial settings decades earlier. 33Pierre Olivier-Méthot and Bernardino Fantini's work has complemented such arguments, emphasizing that EIDs drew attention to the importance of disease ecology because they did not necessarily emerge from "particularly virulent germs," but rather from "significant ecological changes within an ecosystem" and through "cultural and socio-economic factors" in human populations. 34Grmek, likewise, interpreted AIDS as "the price we pay for having radically perturbed millenary ecological equilibria." 35ccording to Mark Honigsbaum and Olivier-Méthot, histories of disease ecology in conversation with histories of EIDs allow us both to interpret the past, and to "illuminate current scientific debates around emerging infectious diseases, and the interaction between biological, economic, and cultural factors in current pandemic emergencies." 36 ecological perspective on disease can help us understand contemporary problems with EIDs.Some have even argued that EID's ecology should be brought to the forefront of environmental history.According to Linda Nash, EIDs provoke historians to investigate the relationships between environments and health.Emerging diseases, she argues, make "compelling political reasons for telling the history of disease as an environmental and social story, rather than simply as a medical and personal one." 37According to Nash, from the days of Richard Preston's 1994 sensationalistic nonfiction thriller, The Hot Zone, emerging diseases have often been attributed to environmental degradation. 38Yet despite this recognition, scientific analyses of the "relevance of the environment to disease emergence" have been treated in a "very generic way." 39 To address this problem, historians should write environmental histories which chart the "specific social, economic, and environmental contexts that have produced the conditions conducive to outbreaks of infectious disease." 40stories of human and animal relations may be of particular importance in addressing Nash's concerns.Given the importance of animal to human spillover, human and animal 31  relations have emerged as an important, if relatively small, subfield of EID studies. 41In 2003, Anne Hardy's pioneering article, "Animals, Disease, and Man: Making Connections" drew attention to the relationship between animal and human health since the mid nineteenth century, both in Europe and in European colonies.One particularly important point posed by Hardy was that human intimacies with animals have historically been identified with outbreaks of disease, often through the lens of colonial racial and class prejudices. 42ubsequent studies of SARS and influenza, such as those penned by Lyell Fearnley and Frédéric Keck, have continued to draw attention to how scientists have interpreted human relationships with birds, and how these have led to the positing of new diseases and their transformation into epidemics and pandemics. 43Similarly, Karen Brown's study of resurgent rabies in South Africa demonstrates the need to analyze human/animal relations within environmental, medical, and social history. 44The coronavirus pandemic has also underlined the importance of treating animals as agents of historical change on account of their epidemiological significance.Writing on the history of pangolins, Sujit Sivasundaram has argued that historically "zoonotic transfer occurs where relations between humans and animals have been unstable or where they are entering a new phase of contact." 45Given climate change and the emergence of zoonotic disease, he suggests that scholars write "multi-species and even trans-species history that is about the assembly of various life forms and things generative of historical change." 46ile historical analyses of the emergence of the EID concept and its sociopolitical realities are relatively scarce, scholars of the medical humanities have examined this concept in more detail. 47Some have pointed out that despite issues with the framing of the concept, it has been "immensely successful" in gathering "international resources to fuel the development of new collaborative research…on infectious diseases" that threaten "both the North and the South." 48Lorna Weir and Eric Mykhalovskiy consider the EID a concept that has been successful in altering "understandings of infectious disease in ways that mobilized widespread public health concern over new microbial threats and drove significant institutional change in the scope and form of global public health surveillance and field response," 49 Europe PMC Funders Author Manuscripts

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On the other hand, the successes of this concept have simultaneously exposed its shortcomings.According to Weir and Mykhalovskiy, because the idea of disease emergence has become so popular, global-health funding bodies have prioritized attention to EIDs over endemic diseases that continue to plague parts of Africa, Asia, and Latin America. 50This has compounded preexisting medical funding problems within the South. 51Critical medical anthropologists and specialists in global health in the 1990s and 2000s have likewise drawn attention to geopolitical inequalities and EIDs.For them, emerging diseases were not simply an unavoidable consequence of globalization as their clinical definition implies.Rather, global capitalism played a critical role in the emergence of diseases such as HIV/AIDS.Since the 1990s, anthropologists have produced studies on the "structural violence" that generates vulnerability to diseases such as "poverty and economic exploitation, gender power, sexual oppression, racism and social exclusion." 52To name one prominent example, in 1996, anthropologist and physician Paul Farmer critiqued the definition of EIDs, claiming that it paid insufficient attention to social inequalities, and treated emergence as a somewhat random biological event.To move beyond this problematic approach, Farmer called for a critical epistemology of emerging infectious diseases, and argued that historical, sociological, and anthropological expertise needed to be mobilized to study how inequalities of class, race, gender, and sexuality, facilitated disease emergence. 53Richard Parker, a medical anthropologist who was instrumental in the founding of the Global Public Health journal, also blamed inequalities in the IMF's programs for the breakdown of public health systems in many parts of the world. 54According to Méthot and Fantini, these problems persist to this day.Despite the indebtedness of the EID concept to disease ecological research, many experts still focus "on purely epidemiological and clinical aspects of emerging events" at the cost of ecological and sociological factors. 55Perhaps it would be better, speculate Méthot and Fantini, to refer to EIDs instead as emerging epidemics, because of "enhanced diffusion of pre-existing microorganisms thanks to several factors such as migrations, wars, travels, and trade." 56ucault-influenced anthropologists have likewise devoted attention to the concept of EIDs to explain the cosmological underpinnings of Western medical governance, and the challenges these diseases pose to biopolitics.Carlo Caduff has argued that at "the heart of the concept of emerging viruses is a particular temporality" that "naturalizes the idea of a permanent threat".This "cosmology of mutant strains," which emerged in the early 1980s, draws attention to the "ever-evolving nature of viruses." 57Under this cosmology, medical professionals view nature as "already one step ahead": they are perpetually "struggling to keep up with nature's relentless evolution." 58Expertise is reduced to ignorance: nature produces new viruses before they are even named, and once they have been given a name, Europe PMC Funders Author Manuscripts Europe PMC Funders Author Manuscripts they continue to mutate ad infinitum. 59This "cosmology of mutant strains" constitutes a challenge to biopower and medical triumphalism: since pathogens are always ahead of scientists, the "bold dreams of control and eradication" must be replaced with "modest schemes of response and relief." 60ong with history and anthropology, literary criticism has also provided insights into the birth of the EID concept and its sustained popularity.According to Priscilla Wald, North American publics have primarily been informed about the risks of EIDs through books, newspapers, and movies. 61To Wald, these stories follow a "formulaic plot", derived from past narratives of epidemics and nineteenth-century detective novels.It commonly starts with a mysterious outbreak in an isolated place in Africa or South America.Traveling globalized networks, this faraway menace begins threatening American society.A team of doctors is then called to solve the mystery in a race against time.The heroes eventually succeed: the outbreak is contained and the disease eradicated, at least in the US. 62To Wald, these accounts are a tool "for making the invisible appear": they reveal obscure biological entities and the hidden realities of globalization. 63Ironically, if AIDS gave a new life to the outbreak narrative, its trajectory does not follow the formulaic plot, because it was never totally contained. 64One questions if the ongoing COVID-19 and monkeypox pandemics will have a similar fate.
In short, critical studies of the historical, anthropological, and rhetorical aspects of the EID concept have emphasized not only biological factors, but also the social, political, and economic realities that explain the emergence of the concept, its diffusion and popularization.Such studies have, however, been largely anchored in North American and Western European experiences, paying little attention on how the concept circulated, was adapted, and reconstructed in places such as Latin-America, Africa, and South or East Asia, commonly seen by Westerners as the sources of EIDs.

Disease emergence: an ontological question
As Stephen Morse remarked in his opening paper of the Emerging Infections Diseases journal, in 1995, "infectious diseases emerging throughout history have included some of the most feared plagues of the past." 65This claim showcases, firstly, how history was mobilized by a generation of doctors and scientists to legitimize the EID concept. 66Secondly, it suggests to historians the need to track the ontological emergence of diseases.Indeed, as remarked by historian Monica Green, every disease, from smallpox to Ebola, was at one point emerging.Historians interested in the ontological emergence of a disease

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Europe PMC Funders Author Manuscripts must examine not only the factors that led to the original spillover event, but also those that transformed them into epidemics and pandemics, and what allowed these to persist.Advances in ancient DNA sequencing and medicine, as well as historical sciences are of use here: they allow historians to pinpoint the deep histories of diseases and to challenge established interpretations based only on historical writings. 67As discussed below, this approach to disease emergence has been applied by historians in two different directions: firstly, with an emphasis on the spread of diseases among human communities with little or no immunity, and secondly, with an emphasis on spillover of the disease from animals to humans.
The concept of pathocenosis, as developed by Grmek in 1969, is an important theorical milestone for a reflection on the ontological emergence of diseases. 68According to his definition, pathocenosis is the ensemble of diseases that existed among a population in a given time and space, which tend to stay in equilibrium.However, this equilibrium could be broken by external factors.Two examples are the arrival of black rats to Europe, which led to the Black Death, and the spread of tuberculosis, which led to the retreat of leprosy, since TB provides cross immunity against leprosy's Hansen bacillus. 69 remarked by Méthot, Grmek's insights anticipated some of the main arguments developed by Alfred Crosby in his essay Virgin Soil Epidemics, and by William McNeill in his book Plagues and Peoples, 70 both published in 1976.Synthesizing historical analyses with the most advanced scientific knowledge at his disposal, Crosby stressed how the low-immunity of indigenous Americans to infectious diseases, such as smallpox, brought by European colonizers was a major reason for their demographic collapse and for European conquest. 71McNeill's work complemented this argument and argued that the biggest demographic disasters of humanity, such as the Black Death, the fall of the Aztec and Inca Empires, and the nineteenth century cholera waves, were the result of environmental imbalances caused by the arrival of new diseases to places with nonimmunized populations.For McNeill, imperial expansion and commerce were to blame for the rupture of environmental equilibrium because they connected different environments and allowed people, animals, parasites, and micro-organisms to circulate between them.For instance, the Black Death was directly connected with the expansion of the Mongol Empire, because it bridged plague reservoirs among wild rodents in inner Asia with black rats in Europe. 72It is worth noting that McNeill was the only historian to participate in the 1989 conference that coined the EID concept. 73As he remarked in the introduction to the third edition of Plagues and Peoples in 1998, the spread of HIV/AIDS around the 67 Monica H. Green, "Emerging Diseases, Re-Emerging Histories," Centaurus 62, no. 2 (1 May 2020): 234-47.
world confirmed his arguments of how disease emergence and pandemics are connected with processes of globalization. 74osby and McNeil's interpretation of the conquest of America have, however, been met with criticism, because they offer a fatalistic conclusion that indigenous American populations were fated to disappear once their pathocenotic equilibrium was broken and smallpox and other infectious disease emerged in the Americas, no matter if by violence or by peaceful contact.Their interpretation is however still potent in popular culture, as evidenced by Laurent Binet's novel Civilizations, which won the 2019 Grand Prix du Roman de l'Académie Française.Binet imagines a world where pre-Columbian populations met with Vikings adrift in the Caribbean by the year 1000, from whom they pick-up iron, horses, and smallpox, which became, one could say, part of the American pathocenosis.Therefore, in this imagined past, no demographic annihilation occurs with Columbus' arrival.Smallpox does not arrive in the Americas after 1492 because in his story it had arrived five hundred years earlier.Indigenous Americans managed then to defeat Columbus, seize his caravels, and invade and ultimately conquer Western Europe. 75ong historians, McNeill's argument of how the flow of people and goods between continents led to the emergence of diseases has more recently been examined in Mark Harrison's Contagion.By using modern knowledge on the epidemiology of diseases and archival research, Harrison emphasized the major role played by trade in the circulation of pathogens and vectors, such as rats and fleas, and showed how measures to combat them were as much driven by politics as they were by the threat posed by the disease itself. 76yron Echenberg, likewise, has shown how the sea-traffic of goods, people, and also of rats and fleas between "plague ports" spread plague between 1894 and 1901 from its endemic areas in China to new locations across the globe, including South America, Australia, South Africa and the United States.Echenberg also reflected on why the disease was better controlled in some of these ports than in others.To him, the ports that focused on rat destruction (Rio de Janeiro, Buenos Aires, San Francisco), were more successful in fighting plague emergence thanthe ports of the British Empire, which relied more on disinfection. 77n short, Harrison and Echenberg convincingly showed how political economy and growing global capitalism were important factors in the spread of plague.Nonetheless, the price paid in these two accounts was sometimes to overshadow science's own historicity.For instance, albeit rats and fleas were framed in both books as main villains for the emergence of plague as a global scourge, these animals were not considered as such before the late nineteenth century.Even after that time, vigorous debates took place around the world on the role of rats and fleas in spreading plague and on the feasibility of killing them. 78hn Iliffe's synthesis of the biological and social history of HIV/AIDS in Africa provides another good example of this ontological approach in action, this time focused on social 74   The fact that genetic evidence suggests that "new HIVs emerged multiple times…means they cannot be seen as random or chance events" but instead "a human made disaster." 82 These ontological approaches have thus synthesized modern science and historical methods to pinpoint the appearances of pathogens in periods in which these were not yet mentioned in archives.Moreover, modern epidemiology has allowed historians to reconstruct the probable causes of their spread and understand why some places were more affected than others.Simultaneously, archival work has provided pointers as to the social, economic, and political factors that transformed diseases into epidemics and pandemics.Fascinating as such work is, it has often neglected the epistemology of disease emergence.

Disease emergence: an epistemological problem
Infectious diseases that were emerging, either because they passed from animal to human hosts or started spreading within new communities, were often perceived differently by different peoples.Perhaps one of the richest ways in which historians have engaged with the idea of emerging diseases has been to understand the emergence, or appearance, of diseases in the past as an epistemological and social process.In other words, how and why a disease was considered a new entity followed upon transformations in science or transformations in cultural and social attitudes.A good introduction to theoretical and methodological issues in these matters can be found in Ludwik Fleck's studies on the epistemological and cultural roots of the changing nature of syphilis.Also useful is Charles Rosenberg's concept of framing disease, which stresses the scientific and social forces behind new categorizations of diseases, along with how the biological characteristics of each disease served as limiting factors to social frames. 83To examine the broader historiography on disease emergence as a social and scientific phenomenon, one might focus on plague and on trypanosomiasis, which

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Europe PMC Funders Author Manuscripts is a family of diseases prevalent in sub-Saharan Africa, South Asia, and South America.These two diseases provide an excellent illustration of how social and intellectual changes can (re)invent new diseases.
Plague was reframed by microbiology between the late nineteenth and early twentieth centuries, in the first years of what was later called the "Third Plague Pandemic."Historian Andrew Cunningham examined the transformation of plague by studying the identification of its bacillus during the Hong Kong outbreak of 1894, which started the pandemic.Cunningham argued that the French-Swiss microbiologist Alexandre Yersin and the Japanese microbiologist Shibasaburo Kitasato "had taken into their laboratories a disease whose identity was constituted by symptoms; they had emerged with a disease whose identity was constituted by its causal agent." 84Therefore, Cunningham concluded, Yersin and Kitasato transformed plague's identity, because from 1894 onwards, a plague outbreak would be declared only after its bacillus was identified in a laboratory.
More recently, numerous historians have further developed Cunningham's argument.They have shown, for instance, that reframing plague as a microbiological entity involved more than just the identification of the bacillus.It involved the production of sera and vaccines against it, the proposing of theories about its spread, and the invention of new sanitary measures to control the bacillus and its animal "reservoirs."Moreover, reframing plague was more of a global process than assumed by Cunningham.As we have shown in previous works, the microbiological reframing of plague involved a network of actors and laboratories in places such as Brazil, India, and South Africa.Scientific, diplomatic, and imperial forces connected them and knowledge about plague circulated between them and was transformed by them. 85 old diseases were reframed by microbiology, this new science, with the help of tropical medicine and indigenous medical experts, was also responsible for constructing "new" diseases, such as trypanosomiasis in Africa and in South America.African trypanosomiasis is a term that encompasses two diseases -nagana and sleeping sickness -caused by three subspecies of Trypanosoma brucei, a blood parasite transmitted between wildlife, livestock, and humans by the tsetse fly.Both diseases, the former in livestock and the latter in humans, cause progressive, gradual emaciation, along with neurological disturbances,

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Europe PMC Funders Author Manuscripts followed by death.African pastoralists in numerous areas had long contended with these symptoms in livestock, and often attributed them to a disease caused by the bite of the tsetse fly.The term "nagana" itself is an Anglicization of unakane, an isiZulu word that has been translated as "continual pestering action," referring to the infuriating bite of the fly. 86Despite trypanosomiasis's long history under a plethora of different names, numerous historians have argued that it became a problem of colonial governance in the late nineteenth to early twentieth century, during a period in which imperial powers were attempting to develop lands they had violently seized from indigenous people. 87African trypanosomiasis was first identified bacteriologically in the 1890s, in Zululand, and named "tsetse fly disease or nagana" by Scottish-Australian microbiologist David Bruce and his research partner and wife Mary Bruce.Later, it was studied across Africa by a host of scientists.European colonists feared that this disease would become endemic across much of the continent and even spread into other parts of their empires. 88holars such as ecologist John Ford have argued that European activities were at times responsible for the emergence and persistence of trypanosomiasis. 89As Maryinez Lyon notes, in her seminal study of trypanosomiasis in the Belgian Congo, it was a "colonial disease": the political, ecological, and labor disruptions caused by colonial governance created ecological conditions conducive to the emergence of devastating trypanosomiasis epidemics. 90In response, historians have documented how European states attempted to prevent the disease from spreading and how Africans responded to such efforts.This involved the attempted wholesale extermination of wildlife in agricultural areas, trapping and killing tsetse flies in enormous numbers, slashing and burning vegetation in which the flies nested, the forced resettlement of Africans, and ultimately, the dusting and soaking of parts of the continent in DDT. 91In short, although sleeping sickness symptoms were long known in the continent, the disease "emerged" and was framed as a particular concern to colonial powers in the twentieth century due to the scramble for Africa.Colonists transformed it into a persistent series of devastating epidemics, that killed hundreds of thousands of Africans.Changes in human and animal relations were critical here.In Zululand, South Africa, for example, colonial game-protection laws coupled with the suspicion of Zulu ideas that large game was pathogenic, produced significant outbreaks of nagana, and extended its endemic area. 92e emergence of American trypanosomiasis, or Chagas disease, as a new nosological entity in the early twentieth century has intriguing counterpoints to its African counterpart.In 1909, while conducting work on malaria in Lassance, a village in the Brazilian state of Minas Gerais, Carlos Chagas, of the Instituto Oswaldo Cruz in Rio de Janeiro, made a breakthrough discovery.In the blood of a few people that he imagined might be infected with malaria, he found a different parasite, which he christened Trypanosoma cruzi.Following this identification, Chagas located the parasite's vector, known as barbeiro in Brazil, a common blood-sucking insect present in the hinterland of South America that nests in holes in wooden houses.Chagas identified, as a symptom of the disease, lesions in the heart, caused by the parasite, as well as related symptoms, such as fatigue and hyperthyroidism.The path followed by Chagas was unusual, not just because he started from the parasite rather than from the symptoms, but because he made a threefold discovery.Thus, as has been argued, the identification of this new disease demonstrated the Brazilian contributions to the field of microbiology and tropical medicine at the turn of the twentieth century. 93It also fostered connections between Brazilian scholars and their counterparts in scientific centers, such as Germany and France.This carved out a place for Brazil in the global field of tropical medicine. 94wever, as shown by the historian Simone Kropf, "Chagas disease was represented as a medico-scientific entity and at the same time as a social question." 95Indeed, the 1910s-1920s were a period of intense discussion about the problems of Brazilian agriculture, coupled with the commemorations of the first independence centenary in 1922.In this context, Chagas disease was used by medical, political, intellectual elites as "the symbol of a 'sick' and 'backwards' country, devastated by endemics that disable the rural population, but its discovery was also seen "as the herald of [a new] science". 96Therefore, a strong association was formed among the Brazilian elites, which framed Chagas disease as "a disease of Brazil." 97Its presence in the territory was understood as an obstacle to the modernization of the country, which could be overcome through vector-destruction, sanitation, and home-improvement.Thus, the emergence of Chagas disease as a new pathology was intertwined with nation building and modernization projects in Brazil.Therefore, the history of Chagas disease in Brazil, like sleeping sickness in Africa, shows how disease emergence can be a matter of the scientific tools available to a society, and a result of political and social forces. 98

Conclusion
In conclusion, we would like to emphasize some challenges that humanities scholars face in studying the concept of emerging infectious diseases.Firstly, there are several gaps in the historiography of the EID concept, such as its circulation outside the USA and Western Europe, how scientific and political communities in the rest of the world have utilized it, and the evolution of the concept.There is considerable scope for future research into EIDs in global and non-western frameworks, particularly for historians working with multiple archives across various regions.
Secondly, it is worth reflecting on the utility of using techniques such as phylogenetics in tracing the ontological emergence of diseases in the past.On the one hand, they are vulnerable to charges of presentism and problematic in that they take modern science as a series of timeless facts that can be projected onto eras in which such knowledge never existed.On the other hand, when cognizant of this limitation, scientific methods, such as genetic studies, can provide valuable tools for writing histories of the emergence and persistence of the pathogens themselves.They allow historians to demonstrate the impacts of these nonhumans on multispecies demographies and geographies in periods where written records are scarce.Likewise, they can provide counterpoints to the prejudices of colonial archives.
Thirdly, although animals have not escaped the attention of historians of EIDs, there is still much more work to be done on animals as historical subjects in analyses of emerging or re-emergent diseases.Animals have played an important role in the microbiological reframing of old diseases, such as plague. 99

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Europe PMC Funders Author Manuscripts subjects often recede into the background and are cast as tools for human experimentation, vectors of infection, or passive victims of disease control policies, rather than as active beings that have shaped the emergence of diseases, and the knowledge produced about them.
In taking animals seriously as historical subjects, one rich topic of enquiry would be to reverse the standard story of emerging infectious diseases and examine EIDs as a problem of wild animals.In addition to examining how contact with wild animals leads to spillovers of disease into human populations, we might also examine how diseases of humans or domestic animals spill into wild animal populations.Here, scholars could examine the attempts of scientists to protect mountain gorillas from human diseases, African wild dogs from diseases of domestic dogs, or even zoo and farm animals from COVID-19.The relationship between the global movements of animals and disease emergence constitutes another potential area of study.Along with the better-known stories of accidental introductions of rats and insects around the globe, historians could examine the epidemiological consequences of the trade in horses and cattle or wild animals for zoos, the migration of wild animals beyond international borders, or of sea creatures across the oceans.
A final challenge is how to transcend national/local boundaries when a analyzing the epistemological emergence of diseases.While some work has been done here regarding the history of plague, it is still lacking in other areas such as the study of trypanosomiasis.Despite the richness of the works mentioned above, they often regard the framing of trypanosomiasis as new entities as the result of processes sealed within national/imperial borders.However, Chagas disease, nagana, and sleeping sickness emerged almost in parallel, perhaps because both regions were exposed to similar global political, economic, and scientific processes.Thus, future works could highlight the connections between African and South American contexts, along with other places where trypanosomiases were studied, such as India or the Philippines.In short, global histories of disease emergence as an epistemological and social process constitute a promising field that can be developed beyond the cases discussed in this essay.
These are just a few suggestions that can be adapted to the study of the numerous infectious diseases not mentioned here.We have not aimed to be exhaustive, as this might have encompassed much of the history of infectious disease.Moreover, we did not examine the ontological and epistemological emergences of non-infectious diseases, nor how these diseases were examined or neglected by the EID concept.Despite these gaps, we hope our essay has provided a guide to works that have engaged critically with the EID concept, along with studies that, in connection with the burgeoning interest in this concept, have sought to understand the history of the ontological and epistemological emergence of new infectious diseases across space and time.
factors and spillover events that transformed AIDS into a pandemic.Mobilizing up-to-date genetic studies, Iliffe situated the origins of HIV/AIDS within multiple zoonotic spillovers from simians in the 1930s-1950s, which were transformed into a silent epidemic through colonial upheavals, the migration of labor, and the inequalities of capitalism.79Jacques Pépin, a former medical officer in the rural Democratic Republic of Congo, likewise showed how colonial medical interventions, "requiring the massive use of re-usable syringes and needles" helped turn HIV into an epidemic.80Most recently, William Schneider's edited volume on the Histories of HIVs has also demonstrated the potential for syntheses of history and biology in clarifying the emergence of diseases.He sees the history of HIV as key in understanding the future of the COVID-19 pandemic. 81HIV/AIDS, like COVID-19, has provided a painful lesson in how "animal viruses can transition to become epidemic or pandemic human viruses." Weir and Mykhalovskiy, Global Public Health Vigilance, 36.
Moreover, they are commonly blamed for the emergence of new diseases, 100 notably avian influenza, 101 HIV, 102 and more recently, COVID-19.Yet, even in studies that explicitly focus on zoonotic transfers of disease, animal endemic da Silva and Skotnes-Brown Page 15 Isis.Author manuscript; available in PMC 2023 October 06.